Among the acute complications of sickle cell disease, acute stroke is the most devastating one. About 10% of children with the genotype HbSS will develop overt stroke, in the absence of interventions geared toward primary stroke prevention. More 20% to 35% of these children have silent cerebral infarcts, which often leads to cognitive decline. Such infarcts are harbingers for more silent infarcts and overt stroke.
With secondary stroke prevention measures like chronic transfusion programs or hematopoietic stem cell transplantation, recurrence of stroke can range from 46% to 90% in children with sickle cell disease. The observation is that people with HbSC and HbSβ+ thalassemia seldom suffer overt CNS events at any age.
Stroke has a wide variety of presentations, including but not limited to, sudden onset of weakness, inability to talk, seizures or sudden loss of consciousness. Stroke often culminates in adverse motor and cognitive sequelae. In many instances, stroke is preceded by transient ischemic attacks, with neuroimaging being negative and often not predictive of a stroke.
Stenosis or occlusion of the internal carotid or middle cerebral artery leads to an overt stroke. However, in many cases, this is precipitated by acute chest syndrome, parvovirus B19 infection.
Among children with a high risk of stroke based on transcranial Doppler screening, scheduling regular blood transfusions reduces the incidence of stroke.
As with children, adults with HbSS are at an exceptionally high risk of both ischemic and hemorrhagic stroke, with the later being sudden, accompanied by thunderclap headaches and loss of consciousness, and carries a very high mortality.
With the above information, let’s look at the guidelines geared toward the management of acute stroke and prevention of recurrence.
- In people with sickle cell disease who present with severe headache, altered level of consciousness, seizures, speech problems with or without paralysis, evaluate for acute stroke. Seek neurologic consultation and perform an urgent head computed tomography (CT) followed by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) if available.
- In consultation with a sickle cell expert, perform an exchange transfusion in people with sickle cell disease who develop acute stroke confirmed by neuroimaging.
- Initiate prompt evaluation, including neurologic consultation and neuroimaging studies, in people with sickle cell disease who have a mild, subtle or recent history of signs or symptoms consistent with transient ischemic attacks.
- In children and adults who have had a stroke, initiate a program of monthly simple or exchange transfusions.
- In children and adults who have had a stroke, if it is not possible to implement a transfusion program, initiate hydroxyurea therapy.
It is Prudent to acknowledge the scarcity of resources in many remote settings in Africa. A healthcare provider with adequate emergency care skills should be available at any facility with a fully functional ambulance to transfer such patients to hospitals with capabilities to handle people with stroke. Together, we can reduce the incidence of overt stroke among people living with sickle cell disease.
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